Subject: Re: Help
From: Erik Naggum <>
Date: 1998/03/20
Newsgroups: comp.lang.lisp
Message-ID: <>

* temp <>
| Hi I am trying to write an iterative lisp function that given a list A
| returns a list with everything in A repeated twice consecutively.  For
| example A = [a,b,c] then the newlist = [a,a,b,b,c,c]. Any help would be
| greatly appreciated. Thanks.

  first, you have a pretty weird syntax for lists, but I guess you still
  mean lists like (A B C) and (A A B B C C) not something else entirely.

  however, back to your homework assignment: as you may have found out,
  there are many ways to do what you want to do, but I have not yet seen
  the simple _iterative_ solutions:

(loop for e in <list> collect e collect e)

  I'm sure you are not allowed to use LOOP, but rewriting this to use DO or
  DOLIST shouldn't be too hard.

  religious cult update in light of new scientific discoveries:
  "when we cannot go to the comet, the comet must come to us."